Slicing machines are used in actual practice to cut slices of food such as cold cuts, meat, or cheese. The rotating blade is a source of danger. If a user approaches a slicing machine, he may assume that the slicing machine and the blade of the slicing machine are in a safe state, as the machine is not in use. A safe state means the blade is not moving and the stop plate is in a zero position in order to fully cover the cutting edge of the blade. In such a safe state, the risk of injury by the blade due to unintentional touching of the blade is reduced. In practice, it is not guaranteed that a slicing machine, which is not in use, has been brought to a safe state. Especially after close of business, the slicing machine is cleaned by cleaning staff which may have no idea about the state of a slicing machine and just assume that the operating person put the slicing machine into a safe state before finishing work.
During operation, slicing machines as known in the art may indicate if the machine is switched on or off and may also indicate the thickness of slices which are cut from food products in a way to ease the operation. However, they provide no indication regarding a safe or unsafe state of the slicing machine.